Material stitching apparatus

ABSTRACT

Apparatus for facilitating the stitching together of layers of material comprising in combination a sewing machine, the sewing machine including a presser foot, a needle, a drive mechanism for the needle, a control mechanism for starting and stopping the drive mechanism, and a guide; a template, the template comprising a lower plate having a continuous guide track engageable by the guide, first and second top plates, an element pivotally mounting the first and second top plates to the lower plate to be closable over a respective part of the lower plate to hold material to be stitched, the guide track having first starting and finishing points for a stitching operation on material held by the first top plate and second starting and finishing points for a stitching operation on material held by the second top plate, the first and second finishing points being spaced respectively from the second and first starting points, and first operating elements on the template at each of the finishing points; and another drive mechanism for driving the template from the sewing machine so that the guide track follows the guide until one of the operating elements operates the control mechanism to stop the drive mechanism with the needle of the sewing machine at the respective one of the finishing points.

United States Patent [191 Bennison MATERIAL STITCHING APPARATUS [75]Inventor: Michael Newstead Dennison,

Leeds, England [73] Assignee: W. J. Ciarkson Limited, Yorkshire,

England [22] Filed: Oct. 26, 1971 [21] Appl. No.: 192,668

[30] Foreign Application Priority Data Oct. 29, 1970 Great Britain51,443/70 [52] us. c1. 112/121.12 511 111:. C1. nosb 21/00 58 FieldoiSearch 112/121.11, 121.12, 112/121.13, 121.15, 207

[56] References Cited UNITED STATES PATENTS 3,172,379 3/1965 Lightll2/l2l.l2 3,170,423 2/1965 l-lenebry 1 12/l21.12

FOREIGN PATENTS 0R APPLICATIONS 181,490 4/1966 U.S.S.R l12/121.12175,445 7/1953 Austria ll2/12l.15

ifrjmary Examiner-Werner H. Schroeder v Attorney-Richard K. Stevens,Davidson C. Miller et al.

[ Aug. 28, 1973 [57] ABSTRACT Apparatus for facilitating the stitchingtogether of layers of material comprising in combination a sewingmachine, the sewing machine including a presser foot, a needle, a drivemechanism for the needle, a control mechanism for starting and stoppingthe drive mechanism, and a guide; a template, the template comprising alower plate having a continuous guide track engageable by the guide,first and second top plates, an element pivotally mounting the first andsecond top plates to the lower plate to be closable over a respectivepart of the lower plate to hold material to be stitched, the guide trackhaving first starting and finishing points for a stitching operation onmaterial held by the first top plate and second starting and finishingpoints for a stitching operation on material held by the second topplate, the first and second finishing points being spaced respectivelyfrom the second and first starting points, and first operating elementson the template at each of the finishing points; and another drivemechanism for driving the template from the sewing machine so that theguide track follows the guide until one of the operating elementsoperates the control mechanism to stop the drive mechanism with theneedle of the sewing machine at the respective one of the finishingpoints.

10 Claims, 3 Drawing Figures memwwcze um SHEET 1 OF 3 PATENTEDmcea I975SHEET 2 [IF 3 MATERIAL STITCHING APPARATUS This invention relates toapparatus for facilitating the stitching together of layers of material.

ln the manufacture of some articles, particularly parts of garments,certain operations involve the stitching together of at least two layersof material along a desired stitching line. It is known to hold thelayers of material in superposed relationship on a template having aguide track engageable with a guide element on a sewing machine. Thearrangement is such that by moving the template so that the guide trackmoves about the guide element the layers of material are moved beneaththe needle of the machine which passes through material exposed in theguide track so that the material is stitched together along the desiredline.

In stitching articles such as'patch pockets the stitching path to befollowed is not a closed path, but terminates at two spaced points.Accordingly, after one stitching operation, the direction of movement ofa template needs to be changed to return it to its original startingposition. If the template is mechanically driven this calls for areversible drive, or for a disengageable drive so that the template maybe returned by hand. Stitching may or may not be possible on the returnrun, and the arrangement is recognised as being timewasting.

To overcome this it is known to use a double template having two halves,each of which may be operated independently to hold layers of materialto be stitched together. The starting point for the stitching operationon material in one half of the template is adjacent to the finishingpoint for the stitching operation on material in the other half of thetemplate. The template thus calls for drive in a single direction only,and no reverse cycling ofthe template is necessary. However, the twosets of workpieces are stitched together at the adjacent starting andfinishing points, and this is disadvantageous as it results in loadingand unloading difficulties and a separate cutting operation.

According to the present invention a template for facilitating thestitching together of layers of material comprises a lower plate havinga continuous guide track engageable by guide means when in associationwith a sewing machine, two top plates each pivoted to the lower plateand each closable over a respective part of the lower plate to holdmaterial to be stitched, the

guide track having starting and finishing points for a stitchingoperation on material held by each top plate, the finishing pointassociated with one top plate being spaced from the starting pointassociated with the other top plate, and first operating means on thetemplate at each finishing point for controlling an associated sewingmachine to stop the sewing machine at the respective finishing point.

This automatic stopping of the machine at each fin ishing point allows aneedle positioning and thread trim operation to be performed soreleasing the already stitched pieces of material and making the machineready for stitching the pieces of material held in the other part of thetemplate.

The means at each finishing point of the template may take any one of anumber of forms. Preferably the means is a rampadjacent to therespective finishing point and raised above-part of the upper surface ofthe lower plate, engageable by the presser foot of the machine toliftthe pressure foot, the machine incorporating a microswitch or otherswitch responsive to this lifting movementto stop the machine.Alternatively, other forms of an operating member may be provided on thetemplate for directly engaging microswitches mounted on the bed or otherpart of the machine. In a further-alternative the means may be a lighttransmitting or light reflecting part of the template operating aphotocell at;

rangement mounted on the machine. Other arrangements are also possible.

When stitching pocket flaps and other articles it is desirable either toback stitch or to stitch at a higher density at the endparts of thestitching line. To allow for this, the template preferably, has secondoperating means cooperating with control means on the machine to causethe machine to stitch at a higher density within a selected distancebefore the finishing point of each stitching line, and preferably alsothird operating means to cause the machine to stitch at a higher densitywithin a selected distance after the starting point of each stitchingline. Again ramps operating on the pressure foot are preferred, butother microswitch operating, photocell or other means may be used.

The invention also includes apparatus for facilitating the stitchingtogetherof layers of material comprising in combination a sewing machinehaving a drive mechanism, control means for starting and stoppping saiddrive mechanism, and a guide means; a template comprising a lower platehaving a continuous guide track engaged by said guide means, two topplates each pivoted to the lower plate and each closable over a respec-vtive'part of the lower plate to hold material to be stitched, the guidetrack having starting and finishing points for a stitching operation onmaterial held by each top plate, the finishing point associated with onetop plate being spaced from the starting point associated with the othertop plate, and first'operating means on the template at each finishingpoint; and drive means for driving the template from the sewing ma chineso that the guide track follows the guide means until one of theoperating means operates the control means to stop the sewing machine atthe respective one of the finishing points.

The means for driving the template conveniently comprises a memberpivotally mounted on the bed of the sewing machine, a roller rotatablymounted on the member and capable of frictionally engaging an edge ofthe template, means for biasing the roller towards the edge of thetemplate, and means for driving the roller from the sewing machine drivein a given direction of rotation. I

The drive from the sewing machine to the rollerdesirably includes aone-way sprag-type clutch driven by an oscillating member from therocket shaft of the sewing machine. The clutch converts the oscillatorymovement into a unidirectional intermittent rotation of the roller,synchronized with the action of the needle of the sewing machine. Theroller movement is transmitted to the template to move thisintermittently, the synchroni zation ensuring that the template onlymoves when the needle is out of the material held by the template and isstationary when the needle is in the material.

Although a roller is preferred as the final element of this drive it ispossible to use a pinion engaging teeth formed on the edge of thetemplate.

This drive is used while stitching is being carried out, and preferablyseparate drive means are provided for moving the template from onefinishing position to the subsequent starting position. This separatedrive means may conveniently comprise a pawl engageable with the rollerwhen moving in said given direction for rotation, and slipping over theroller when moving in the opposite direction, and means for moving thepawl in an arcuate path about the axis of rotation of the roller. Thepawl may be carried on any arm pivotally mounted about the axis ofrotation and drivableby a pneumatic ram.

The invention may be used in conjunction with a pure sewing machine, orwith the type of machine that, as well as stitching, simultaneously cutsthe material being worked along a line complementary to and outside thestitching line.

A particular embodiment of the invention will now be described in moredetail, by way of example only, with reference to the accompanyingdrawings in which:

FIG. 1 is a schematic exploded view of parts of a sewing machinemodified in accordance with the invention.

FIG. 2 is a plan view of part of the apparatus; and

FIG. 3 is a cross-section on the line Ill-Ill of FIG. 2 with some partsomitted for clarity.

The apparatus includes a template 1 having a lower plate 2 formed with acontinuous guide track 3 engaging a part cylindrical guide member 3asecured to the throat or needle plate of the machine and having a holeand a slot therein for receiving respectively a needle and a knife. Twotop plates 4 and S are hinged to the lower plate by hinges 6 and 7respectively, and a tension spring 8 between the top plates biases theseto an open position raised from thelower plate 2. The template may haveinterposed plates with complementary openings or recesses in the topplates to provide a fulling action on at least the upper layer ofmaterial placed in the template. The template is divided into twodistinct stitching areas, one extending round the outer edge of topplate 4 from point 9 to point 10, and the other extending round theouter edge of top plate from point 11 to point 12. The starting points 9and 11 of the two tracks are each spaced from the finishing point 12 or10 respectively of the other track. Adjacent to each starting point 9and 11, the upper surface of the lower template carries a single stepcam block 13 and 14 respectively. Adjacent to each finishing point 10and 12, the upper surface of the lower template carries a two step camblock 15 and 16 respectively.

The outer edge 17 of the template is received in a V- shaped slot 18formed in the edge of a roller 19 rotatably mounted at the end of onearm of a lever 20 pivoted at 21 to the bed of the machine, the pivotincluding roller bearings 22 to ensure low frictional resistance topivotal movement. The other arm 23 of the lever 20 has one end of atension spring 24 anchored thereto, the other end of the spring beinganchored at 25 to the bed. The spring biases the lever counterclockwiseabout its pivot to press the roller 19 into engagement with the edge 17of the template and so wedge the edge of the template into the slot 18.

The roller 19 is driven in a clockwise direction as seen in FIG. 2, fromthe conventional rocker shaft of the sewing machine. A vertical armsecured to the rocker shaft is also pivotally secured to one end of ahorizontal arm 26 which is thus driven from the rocker shaft tooscillate in the direction shown by the double ended arrow. The otherend of the arm 26 is pivoted at 27 to a drive input member 28 of aone-way spray-type clutch 29, the output member 30 of which is connectedto rotate the roller 19. The clutch is of a known type and acts so thatas the input member 28 is driven clockwise by the arm 26 the outputmember 30 and thus the roller 19 are also driven clockwise, but when theinput member is driven anti-clockwise this free wheels relative to theoutput member so that the roller 19 remains stationary.

It will thus be seen that the intermittent rotation of the roller 19from the sewing-machine drive, gives a positive, intermittent drivingmovement to the template to drive this so that the track 3 follows theguide member 3a. This movement will be synchronized to the machineneedle movement so that the template is stationary when the needle is inmaterial held by the template and is moving when the needle is raisedout of the material. The material exposed in the track 3 of the templateis thus stitched by the needle as the template is driven by roller. 19.

While either of the distinct stitching areas of the template is beingdriven past the needle, material exposed in the guide track is beingstitched at the stitch density set on the sewing machine, and thematerial is being cut outside the stitching line. Towards the end point12 of the stitching line the presser foot of the machine, which has beenriding on the surface of the top plate 5, encounters the first section51 of the two step cam block 16. This partly lifts the presser foot, andthis lifting movement is transmitted by a linkage 52 to a lever 53pivotally mounted at 54 to a fixed part of the machine bed. The free endof the lever 53 carries an operating member 55 which, when the presserfoot is so lifted, operates a microswitch 56 to control a solenoidoperated pneumatic valve 57. The valve then admits air under pressure toa cylinder 58 to move a piston in the cylinder so that a piston rod 59moves the usual stitch density control lever 60 of the machine to ahigher stitch density setting. Thus, engagement of the section 51 withthe presser foot initiates higher density stitchmg.

Further movement of the template then causes the presser foot to ride onto the second section 61 of the two step cam block 16. This furtherlifts the presser foot, and the operating member 55 is then moved tooperate a further microswitch 62. This controls operation of a solenoidoperated pneumatic valve 63, to allow fluid to flow to cylinder 63a thepiston end of which moves a lever 64 about a fixed pivot 65 to move thecontrol pin 66 associated with the machine motor 67. Movement of thecontrol pin stops the motor 67, so that both stitching and driving ofthe template cease, and then actuates the needle position and threadtrim systems which are conventionally build into industrial sewingmachines. The needle is thus lifted from the workpiece and the thread iscut so releasing the stitched material from the machine. The raising ofthe presser foot allows the top plate 5 of the template to be lifted bythe spring 8 so that the stitched material may be removed from thetemplate. The top plate 4 of the template is also in a raised positionso that further material to be stitched can be placed beneath top plate4.

When this has been done a separate control, which may conveniently be afoot-operated pneumatic valve 68, is operated. This admits air underpressure to a cylinder 69, the piston rod 70 of which pulls lever 53further downwardly and so raises the presser foot 50 fully clear of thetemplate. Microswitches 56 and 62 remain operated, so that the motor 67is stopped. Operation of the valve 68 also applies air to a cylinder 71,the piston rod of which lifts the knife trimmer so that the knife 71a israised to a position raised clear of the template.

Operation of the valve 68 is also effective to cause the template to bedriven from the finishing position 12 to the subsequent startingposition 9. To this end, and referring more particularly to FIG. 2, thevalve admits compressed air to a cylinder 72 to extend a piston rod 73from the cylinder. The piston rod 73 is pivoted at 74 to one end of anarm 75, the other end of which is pivoted at 76 to a lever 77 rotatablymounted about the axis of rotation of the roller 19. The lever 77carries a from the finishing position 12 to the next starting position9.

The apparatus is then ready for a further stitching operation. Toinitiate this the foot is withdrawn from'the valve 68 to allow this toresume its position. A spring 79 then returns the lever 77 andassociated parts to their original position, the pawl 78 riding freelyover the knurled edge of the roller 19. Springs also return the knifetrimmer to the knife lowered position, and the presser foot 50 to itslowered position to contact the single step cam block 13. The operatingmember 55 clears microswitch 62 so that the control pin is moved to thedrive position and the motor thus starts the template driving and thestitching operations. The single step cam block 13 holds the presserfoot partially lifted so that microswitch 56 is operated and the stitchdensity control lever is held in its higher density position to givehigh density stitching over the first partof the stitching line. Whenthe template has been movedsufficiently for the presser foot to ride offthe block 13, the foot is in its fully lowered position and microswitch56 is released so that the stitch control lever is returned to itsnormal setting and stitching at normal density takes place until thepresser foot engages the first part of the two-part cam block 15 at theend of this stitching path. The sequence described then resurs at theother end of the stitching pathv under the control of cam blocks 15 and14.

It will be appreciated that the apparatus is not limited to theparticular drive system shown, nor to the particular lever and springsystem for biasing the roller into engagement with the template.Although a knurled roller is preferred, a smooth one may be used,perhaps in conjunction with a knurled edge template, and it is alsopossible for both the roller and the template to be toothed. The guidemeans on the sewing machine need not be on, the needle plate but could,for example, be a roller on the presser foot engaging a guide track inthe upper one of the templates.

Means other than the cam blocks 13 to 16 may be used for controlling themachine. For example, the machine may have photoelectric apparatusresponsive to light transmitting or light reflecting parts of thetemplate. The particular elements for controlling the stitch density,drive, needle positioning, knife trimming and thread trimming functionsof the machine may be varied. The arrangement for. moving the templatefrom one finishing position to the subsequent starting position may alsotake any one of a number of forms and is not limited to the pawlarrangement described,

I claim:

1. Apparatus for facilitating the stitching together of layers ofmaterial comprising in combination a sewing machine and a template; saidsewing machine including a fixed bed; guide means on said fixed bed; apresser foot which rides on a surface of said template; a needle; aneedle drive mechanism; a template drive mechanism comprising a memberpivotally mounted on said fixed bed, a roller rotatably mounted on saidmember, means, connected to said needle drive mechanism, for drivingsaid roller, and means, connected to said member, for biasing saidroller to a position frictionally engaging an edge of said template; acontrol means .responsive to the position of said presser foot forstarting and stopping said needle drive mechanism and said templatedrive mechanism; and said template comprising a lower plate, first andsecond top plates, means for pivotally mounting said first and secondtop plates to said lower plate, said first and second top plates beingclosable each over a respective part of said lower plate to holdmaterial to be stitched, a continuous guide track formed in said lowerplate and engaged by said guide means, said guide track having firststarting and finishing points for a stitching operation on material heldby said first top plate and second starting and finishing points for astitching operation on material held by said second top plate, saidfirst and second finishing points being spaced respectively from saidsecond and first starting points; and a plurality of first operatingmeans, on said template at each of said finishing points, for engagingwith said presser foot to operate said needle and template drivemechanisms when said engagement occurs.

2. Apparatus as claimed in claim 1 wherein said control means isresponsive to the raising of said presser foot above a predeterminedheight relative to said fixed bed to stop said drive mechanisms, saidpresser foot rests on an upper surface of said lower plate whilestitching is in progress, and each of said first operating means is aramp adjacent the respective one of said finishing points, said presserfoot being engaged with each said ramp to be raised above saidpredetermined height.

3. Apparatus as claimed in claim 1 wherein said sewing machine furthercomprises a stitch density control means responsive to the position ofsaid presser foot for controlling the stitching density, and saidtemplate further comprises a plurality of second operating means, inadvance of said first operating means, for engaging with said presserfoot to operate said stitch density control means to increase the stitchdensity for a time prior to stopping of said needle and template drivemechanisms.

4. Apparatus as claimed in claim 3 wherein said template furthercomprises a plurality of third operating means, in the region of each ofsaid starting points, for engaging with said presser foot to operatesaid stitch density control means to increase the stitch density for atime after commencement of stitching.

5. Apparatus as claimed in claim 4 wherein said control means isresponsive to the raising of said presser foot above a predeterminedheight relative to said fixed bed to stop said needle and template drivemechanisms, said stitch density control increases stitch density onraising said presser foot to an intermediate height below saidpredetermined height, said presser foot rests on an upper surface ofsaid lower plate while stitching is in progress, each of said firstoperating means is a ramp adjacent the respective one of said finishingpoints, said presser foot being engaged with each said ramp to be raisedabove said predetermined height, and each of said second and thirdoperating means is a further ramp adjacent said respective starting andfinishing points on to which further ramps said presser foot runs to beraised to said intermediate height.

6. Apparatus according to claim in which said first and second operatingramps are contiguous, with said first operating ramp following and beinghigher than said second operating ramp.

7. Apparatus according to claim 1 in which said sewing machine furtherincludes a rocker shaft and said means for driving said roller includesan oscillating member converted to said rocker shaft, and a one-waysprag-type clutch driven by said oscillating member.

8. Apparatus according to claim 1 in which separate drive means areprovided for moving said template from said first finishing position tosaid second starting position, and from said second finishing positionto said first starting position.

9. Apparatus according to claim 8 in which said separate drive meanscomprises a pawl engaged with said roller when moving in a givendirection of rotation, and slipping over said roller when moving in theopposite direction, and means for moving said pawl in an arcuate pathabout an axis of rotation of said roller.

10. Apparatus according to claim 9 in which said separate drive meansincludes a pneumatic ram and said pawl is carried on an arm pivotallymounted about said axis of rotation and drivable by said pneumatic ram.

1. Apparatus for facilitating the stitching together of layers ofmaterial comprising in combination a sewing machine and a template; saidsewing machine including a fixed bed; guide means on said fixed bed; apresser foot which rides on a surface of said template; a needle; aneedle drive mechanism; a template drive mechanism comprising a memberpivotally mounted on said fixed bed, a roller rotatably mounted on saidmember, means, connected to said neeDle drive mechanism, for drivingsaid roller, and means, connected to said member, for biasing saidroller to a position frictionally engaging an edge of said template; acontrol means responsive to the position of said presser foot forstarting and stopping said needle drive mechanism and said templatedrive mechanism; and said template comprising a lower plate, first andsecond top plates, means for pivotally mounting said first and secondtop plates to said lower plate, said first and second top plates beingclosable each over a respective part of said lower plate to holdmaterial to be stitched, a continuous guide track formed in said lowerplate and engaged by said guide means, said guide track having firststarting and finishing points for a stitching operation on material heldby said first top plate and second starting and finishing points for astitching operation on material held by said second top plate, saidfirst and second finishing points being spaced respectively from saidsecond and first starting points; and a plurality of first operatingmeans, on said template at each of said finishing points, for engagingwith said presser foot to operate said needle and template drivemechanisms when said engagement occurs.
 2. Apparatus as claimed in claim1 wherein said control means is responsive to the raising of saidpresser foot above a predetermined height relative to said fixed bed tostop said drive mechanisms, said presser foot rests on an upper surfaceof said lower plate while stitching is in progress, and each of saidfirst operating means is a ramp adjacent the respective one of saidfinishing points, said presser foot being engaged with each said ramp tobe raised above said predetermined height.
 3. Apparatus as claimed inclaim 1 wherein said sewing machine further comprises a stitch densitycontrol means responsive to the position of said presser foot forcontrolling the stitching density, and said template further comprises aplurality of second operating means, in advance of said first operatingmeans, for engaging with said presser foot to operate said stitchdensity control means to increase the stitch density for a time prior tostopping of said needle and template drive mechanisms.
 4. Apparatus asclaimed in claim 3 wherein said template further comprises a pluralityof third operating means, in the region of each of said starting points,for engaging with said presser foot to operate said stitch densitycontrol means to increase the stitch density for a time aftercommencement of stitching.
 5. Apparatus as claimed in claim 4 whereinsaid control means is responsive to the raising of said presser footabove a predetermined height relative to said fixed bed to stop saidneedle and template drive mechanisms, said stitch density controlincreases stitch density on raising said presser foot to an intermediateheight below said predetermined height, said presser foot rests on anupper surface of said lower plate while stitching is in progress, eachof said first operating means is a ramp adjacent the respective one ofsaid finishing points, said presser foot being engaged with each saidramp to be raised above said predetermined height, and each of saidsecond and third operating means is a further ramp adjacent saidrespective starting and finishing points on to which further ramps saidpresser foot runs to be raised to said intermediate height.
 6. Apparatusaccording to claim 5 in which said first and second operating ramps arecontiguous, with said first operating ramp following and being higherthan said second operating ramp.
 7. Apparatus according to claim 1 inwhich said sewing machine further includes a rocker shaft and said meansfor driving said roller includes an oscillating member converted to saidrocker shaft, and a one-way sprag-type clutch driven by said oscillatingmember.
 8. Apparatus according to claim 1 in which separate drive meansare provided for moving said template from said first finishing positionto said Second starting position, and from said second finishingposition to said first starting position.
 9. Apparatus according toclaim 8 in which said separate drive means comprises a pawl engaged withsaid roller when moving in a given direction of rotation, and slippingover said roller when moving in the opposite direction, and means formoving said pawl in an arcuate path about an axis of rotation of saidroller.
 10. Apparatus according to claim 9 in which said separate drivemeans includes a pneumatic ram and said pawl is carried on an armpivotally mounted about said axis of rotation and drivable by saidpneumatic ram.